The key part of my build is to keep it a 230, not stroke or overbore it. Keeping it the same size. I have a lead and a plan slowly taking shape for a 292. I doubt a 230 would *need* bigger valves to run ok. Comparing it to a modified 292 makes no sense. That's a helluva lot bigger air pump with the same head on top. I'm comparing mine to what it was, a 230.
My point was that cheap power is to add cubic inches. But your wanting stock size to experiment with. Also my other point was that because your dealing with a very Small amount of cubic inches I wouldn't be expecting a whole lot. Unless you put it in a 1500 pound roadster or something light, then you might see that engine wake up a bit more. Keep in mind the 230,250,292 all had the same bore size. More air flow doesn't hurt. The 1.72 intake is rather restrictive, not mentioning that head bolt boss. And I'm not Comparing it to a 292, I'm Saying that adding cubic inches Helps. lol Hence why I mentioned stroking it to a 250.
